Customers in Atlanta and Nashville will be the first to receive what United States telecommunications provider Comcast has said is the world's first gigabit internet service using the DOCSIS 3.1 standard.

The pair of cities will receive the improved cable internet service in the first half of this year, with Chicago, Detroit, and Miami set to follow in the latter half of the year.

The company hailed DOCSIS 3.1 as a major step forward in the evolution of ultra-high-speed broadband.

"Because the new network technology allows consumers to receive gigabit internet speeds over an existing connection, it has the potential to make ultra-fast speeds available more widely than fiber-to-the-home services, which typically require new construction and specialized installations," it said.

"The beauty of DOCSIS 3.1 is that it is backwards compatible, so no digging up streets or backyards," Comcast executive vice president and CTO Tony Werner said at the time.

"This technology, when combined with the extensive upgrades we have already completed on our advanced hybrid fiber-coaxial network, will provide more gigabit choices for our customers."

Comcast already offers a 2Gbps symmetrical fibre-based service, dubbed Gigabit Pro, in Atlanta, Chicago, Detroit, Miami, and Nashville. The company said Gigabit Pro is available to 18 million customers across the US.

Earlier this week, Chinese hardware giant Huawei announced that it had teamed up with Tele Danmark Communications to upgrade Denmark's fixed broadband network to deliver download speeds of up to 1 gigabit per second by the end of 2017. Denmark is set to become the first nation with a network upgraded to Giga Coax technology after work begins in June.

Approximately 34 percent of Australia's National Broadband Network (NBN) is set to be served by hybrid fibre-coaxial cable upgraded to DOCSIS 3.1.

"We plan to run DOCSIS 3.1 trials in 2016, and we plan to have DOCSIS 3.1 services commercially available in 2017," wrote Communications Minister cum Prime Minister Malcolm Turnbull a year ago.

In November, a leaked draft from NBN stated that the Optus HFC network is "not fully fit for purpose".